The K-x is responsive - it just snaps an image like an analog cam, the focus delay is so short, it is easy to deal with and just feels plain fast!
Mind you, we are so spoiled these days (at 45 I am not an old foggy yet, but my first real cam was GOSH all manual and - GOSH - had no electronic chips in it!), and realistically, the K100d is faster than doing manual focus on any old manual film SLR, but the K-x is just plain - BANG HERE IT IS - fast!
I tried many cameras, and this is the ONE that fits my hand AND is snappy.
Pentax must have heard us, because gone are the days when I lusted for a Canikon despite my glass investment!
I will keep my K100d bodies and the K20d as backups and the K100d is very comfortable to hold for me (love fumbling it, feels sooo nice ...... never mind ...), but the K-x is the one in the go-bag!
And for the first time I even have a wee bit of a "flashy" factor, being the white "Star Wars Storm Trooper" model - heee heeee ...